Copying the davits of the original ship, I realised that one can make them purely gravity activated. As the winch pays out the weight of the landing craft takes the davit to the outboard position. There is a lug on the davit that prevents it going beyond its outboard position. The landing craft has a sling that can't go through the pulley at the end of the davit.
When the landing craft is raised, the davit will stay in the outboard position by gravity until the sling reaches the pulley and then the davit is raised into the inboard position. As it reaches its final position the davit touches a micro switch that shuts off the winch.
One cable does the whole job, though that is of course doubled per landing craft. All the landing craft are going to be operated by one winch - they will all lower at the same time though only one micro switch will control all of them. I think I shall use elastic thread so there is no danger of over winding the winch and damaging the davits.
Lot of progress today, with all the davits in place, the air conditioning vents in place, and aerials. I'll try and get a couple of photographs up of the latest - it really is coming together. I just have the two landing craft in the stern to complete and some tidying up of the paint work, and the electronics and lighting wired up.